1. Field of the Invention
The present invention relates to an ice detection device adapted for use in an ice storage bin to detect ice pieces supplied into and stored in the ice storage bin from an ice making mechanism, and more particularly to an electromagnetic ice detection device arranged to deactivate the ice making mechanism when detected the ice pieces fully stored in the ice storage bin.
2. Description of the Prior Art
In Japanese Utility Model Laid-open Publication 56-60188, there has been proposed an electric ice detection device of the type as shown in FIG. 4, which includes a tubular guide rod 12 fixed at its upper end to a removable lid 11a of an ice storage bin 11 and extended into the interior of the storage bin 11, a float plate 13 mounted for vertical movement on the guide rod 12, and an electromagnetic switch 14 disposed within an upper portion of the guide rod 12 to cooperate with a permanent magnet 15 mounted on the float plate 13 for detecting ice pieces supplied into and stored in the ice storage bin 11. When the ice storage bin 11 is filled with ice pieces supplied from an ice making mechanism 10, the float plate 13 is raised by the supplied ice pieces to an uppermost position so that the electromagnetic switch 14 is operated by the magnetic flux of permanent magnet 15. In Japanese Utility Model Laid-open Publication 59-178572, there has been proposed an electric ice detection device of the type as shown in FIG. 5, which includes a movable support rod 16 assembled with a lid 11a of an ice storage bin 11, a float plate 17 fixed to the lower end of support rod 16 to be raised by ice pieces supplied into and stored in the storage bin 11, a stopper 18 fixed to the upper end of support rod 16, and a microswitch 19 of the normally closed type mounted on the lid 11a of storage bin 11 and provided with an operation lever 19a in engagement with the stopper 18. When the ice storage bin 11 is filled with ice pieces supplied from an ice making mechanism 10, the float plate 17 is raised by the supplied ice pieces to move the stopper 16 upward to an uppermost position so that the operation lever 16 is released to turn off the microswitch 19.
In the former ice detection device shown in FIG. 4, the tubular guide rod 12 is brought into contact with the supplied ice pieces in accordance with upward movement of the float plate 13. This causes fine ice pieces to adhere to the outer circumference of guide rod 12 and to obstruct the upward movement of float plate 13. In the latter ice detection device shown in FIG. 5, the operation lever 19 is mechanically displaced by the stopper 18 to control on-off operation of the microswitch 19. It is, therefore, apparent that the support member of operation lever 19a will be deformed by use of the ice detection device for a long period of time to cause malfunction of the detection device.